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Query: UMLS:C0149871 (deep vein thrombosis)
 12,364 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although heparin has been used extensively to treat Deep Venous Thrombosis (DVT) and arterial ischemia (AI), controversy still exists regarding optimal dosage and the need for monitoring. Different authors have employed various test with variable results. Others, however, persist in giving heparin without laboratory control. This study was made in order to compare, in a prospective, randomized and blind manner, two coagulation tests, namely: Howel Time (HT) and Activated Partial Thromboplastin Time (APTT), in controlling the dose of heparin given by continuous intravenous infusion in DVT and AI. Our results show no significant difference in complications and failures of the therapy with either test, although significantly higher doses of heparin were needed to maintain APTT within therapeutic range than those needed to keep HT within a similar range.
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PMID:Laboratory control of continuous intravenous heparin therapy with Howel time and activated partial thromboplastin time. A prospective, randomized and blind study. 402 44

In the sequential thrombolytic therapy with porcine plasmin and low dose streptokinase side effects are mainly due to bleeding, intolerance reactions are less important. Treatment had to be prematurely stopped in 42 (37%) of 114 DVT cases because of severe bleeding and in 12 (10%) due to intolerance reactions. The corresponding figures for the 45 cases with arterial occlusions are 15 (33%) and 2 (4%) respectively. The intensity of systemic proteolysis as represented by the thromboplastin time is significantly correlated with haemorrhagic manifestations. Macrohematuria and bleeding from puncture sites are the most frequent haemorrhagic complications followed by spontaneous bleeding into skin and muscles. Non-fatal intracranial bleeding occurred in 1 DVT case (0.9%) and in 2 patients with arterial occlusions (4.4%). The benefit of this potent thrombolytic regimen would greatly improve if a strong reduction of premature treatment stop could be achieved.
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PMID:Side effects of thrombolytic treatment with porcine plasmin and low dose streptokinase. 621 82

From 1971-1982 121 patients with arterial occlusions of the lower limbs underwent systemic thrombolysis treatment at the Kantonsspital Basel. During 4 time-periods, 3 different treatment schedules were evaluated consecutively: a) individually titrated high dose streptokinase (SK), b) individually titrated low dose SK and c) p-plasmin, followed by low dose SK-infusion. Thrombolytic success rates did not differ significantly with the 3 treatment schedules. Nevertheless, the p-plasmin-SK scheme tended to the thrombolytically more effective (68%) than high-dose (58%) or low-dose (50%) SK. The most frequent side effects were bleeding complications. In 6 out of the 121 patients, intracranial bleeding occurred and was lethal in 1 of the patients. The incidence of this most serious complication of 4/47 during the sequential p-plasmin-SK schedule led the authors to abandon this scheme for the treatment of arterial occlusions. The intracranial bleeding complications are much less frequent in patients with deep venous thrombosis undergoing systemic thrombolysis, and hence seem to be due in part to the generalized arteriopathy often present in patients with arterial occlusions. The p-plasmin-SK schedule induced the strongest systemic proteolysis in the light of thromboplastin time and factor V values. Comparison of these data with those of other authors is very difficult because of differences in patient selection, treatment schedules and observance of contraindications. The serious prognosis for patients with acute arterial occlusions, with an overall hospital mortality of 26% (experience at the Kantonsspital Basel, 1978-1982) relativizes the importance of the side effects due to systemic thrombolysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Systemic thrombolysis of arterial occlusions of the lower extremities. Comparison of various treatment schedules]. 622 92

In a group of 10 women with circulating lupus anticoagulant 25 intrauterine deaths were previously documented in the nine multigravidae. The presence of lupus anticoagulant activity was confirmed by showing prolongation of the activated partial thromboplastin time and kaolin clotting time with failure of correction of the prolongation on incubation with normal plasma. A clinical diagnosis of systemic lupus erythematosus (SLE) was made in four women. Three had deep vein thrombosis in pregnancy, one chorea gravidarum while two had only recurrent fetal losses. All the women had positive antinuclear antibody tests and blood platelet counts less than 175 X 10(9)/l. Anti-smooth muscle antibody and VDRL tests were each positive in half the patients; anti-DNA antibody was present in two patients with clinically active SLE. In six pregnancies correction of the activated partial thromboplastin and kaolin clotting time was attempted using prednisone (40-60 mg/day); aspirin, 75 mg/day, was added. Five live infants were obtained, four by spontaneous delivery, when the restoration of the clotting abnormalities to normal was achieved. In one woman presenting with extensive deep vein thrombosis a live infant was delivered following therapeutic doses of heparin and low dose aspirin. Maternal lupus anticoagulant activity has major implications for pregnancy and should be excluded in women with a clinical suspicion of SLE, a positive antinuclear antibody test, thrombotic episodes, biologically false-positive VDRL and unexplained late or repetitive early fetal losses.
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PMID:Lupus anticoagulant in pregnancy. 642 2

In a prospective study, 280 patients with phlebographically proven deep venous thrombosis received intravenous heparin infusion; 224 of the patients were subjected to control phlebography after 5-8 days of treatment. Females above 70 years showed least phlebographic improvement despite similar heparin dosage and heparin activity. Heparin activity in daily drawn blood samples was determined by four different assays. Chromogenic substrate (CS) assay (Coatest heparin), activated partial thromboplastin time (Cephotest), and thrombin time with recalcified plasma (CaTT) showed weak but significant correlations with thrombus resolution judged by phlebography (p = 0.004, 0.003 and 0.018, respectively). A linear prediction equation showed that the phlebographic result was about equally influenced by the mean dose and by the result of any of the three heparin assays. Thrombin time with citrated plasma showed no correlation. CS assay and CaTT showed significantly lower mean heparin activity in patients with (n = 13) than without clinically diagnosed pulmonary embolism (p = 0.012 and 0.001, respectively).
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PMID:The antithrombotic effect of heparin in deep venous thrombosis: relation to four heparin assays. 649 86

Six episodes of lower extremity hemorrhage occurred in five spinal cord injured patients receiving therapeutic anticoagulation. Factors contributing to hemorrhage included excessive anticoagulation in two episodes and soft tissue trauma during vigorous range of motion (ROM) exercises in three. The three episodes without clinical evidence of trauma were initially misdiagnosed as recurrent deep venous thrombosis. Ecchymoses developed in three episodes, but were delayed in appearance in two. Noninvasive vascular tests yielded false positive results in two out of three cases. Venograms performed in four episodes were negative for thrombosis. Based on this experience, the initial investigation of lower extremity swelling in this setting should include: a search for evidence of trauma, analysis of medications for coagulation-related interactions, leg x-rays, and early determination of hemoglobin, prothrombin or partial thromboplastin time, and platelet count. If there is any question of acute thrombosis, a venogram, rather than noninvasive vascular studies, must be performed. All persons involved in the care of these patients should be aware of the increased risk of bleeding and should perform ROM exercises of weak or paralyzed extremities with caution.
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PMID:Lower extremity hemorrhage in spinal cord injured patients receiving therapeutic anticoagulation. 671 54

The efficacy of low-molecular-weight heparin as a prophylactic agent was assessed in 150 consecutive patients over the age of 40 undergoing major abdominal surgery. Fifty of these patients received 1250 activated partial thromboplastin time (APTT) units of low-molecular-weight heparin every 12 hours: three developed isotopic deep vein thrombosis, which was confirmed by phlebography in two cases. The other 100 patients received a single injection of 1850 APTT units of low-molecular-weight heparin. Three of them developed isotopic deep vein thrombosis; phlebography failed to confirm the presence of thrombi in each case. None of the 150 patients studied died from fatal or contributory pulmonary emboli. Low-molecular-weight heparin was not associated with any increase in preoperative or postoperative bleeding. The effect of equal amounts of postoperative bleeding. The effect of equal amounts of low-molecular-weight heparin and unfractionated heparin on the coagulation mechanism during surgery was investigated in another 30 patients. The clotting assays and results of in-vivo platelet function tests indicated that both preparations produced similar effect. Intragroup comparisons, however, showed significant differences in the anti-factor Xa activity, lipoprotein lipase release, and plasma prekallikrein concentrations. A single injection of low-molecular-weight heparin daily is a convenient way of preventing deep vein thrombosis in high-risk patients undergoing major abdominal surgery.
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PMID:Low-molecular-weight heparin and prevention of postoperative deep vein thrombosis. 680 Apr 65

The activated partial thromboplastin time has been used to monitor the effects of low-dose subcutaneous heparin in two groups of patients undergoing hip surgery. The study was performed to determine the degree of anticoagulation required to protect these high-risk patients from post-operative deep vein thrombosis. The patients were randomised to receive a fixed regimen of subcutaneous calcium heparin (5,000 units eight-hourly) or a dose of calcium heparin monitored by maintaining the standardised APTT at 50 secs. In the adjusted group the APTT achieved the target figure in 46% of observations compared to 27% in the fixed group (p less than 0.005). Nine patients showed positive 125I-fibrinogen scans and in all, the APTT was below the target value the day before the scan became positive. In contrast, in six of the nine thrombotic patients heparin was detected by antifactor Xa clotting assay. The APTT, therefore, appears to give a better guide to the antithrombotic effect of heparin than the antifactor Xa clotting assay. These preliminary observations suggest that prolonging the standardised APTT method to just above 50 secs improves prophylaxis in high-risk cases. Furthermore, an increased dose of heparin is required than is proved during the conventional low-dose regime of 5,000 units tds. With regular control using the standardised APTT, increasing the dose to the target value does not increase post-operative haemorrhage. Further studies with larger numbers of patients are required in order to show a significant reduction in the incidence of post-operative deep vein thrombosis in hip surgery patients receiving low-dose adjusted heparin.
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PMID:An evaluation of APTT monitoring of low-dose heparin dosage in hip surgery. 707 5

The goal of heparin therapy in deep vein thrombosis is to prevent thrombus extension. The relationship between thrombus extension and the results of coagulation tests used to monitor heparin therapy is unclear. To explore this relationship, we studied the effect of several heparin regimens on the accretion of indium-111-labeled platelets on fresh venous thrombi, as detected by gamma imaging, and monitored the activated partial thromboplastin time (APTT). Six dogs were treated with a 300-U/kg bolus of heparin followed by a 90-U/kg/hour heparin infusion, a dose of heparin sufficient to increase the APTT to levels greater than eight times baseline (APTT ratio); platelet accretion (thrombus imaging) occurred only after the heparin effect was reversed with protamine sulfate. Nineteen dogs were treated with a 150-U/kg bolus of heparin followed by a 4-hour, 45-U/kg/hour heparin infusion; a thrombus was demonstrated only after protamine injection in 12 (mean APTT ratio 1.3 +/- 0.19) and before protamine injection in seven. In thirteen of these 19 dogs, 30 minutes separated the platelet injection from heparin therapy, while in six this duration was less than 30 minutes. In four of these six dogs, thrombi were demonstrated before protamine therapy and at APTT ratios greater than 3.0. Finally, 10 dogs were treated with a 100-U/kg bolus followed by a 3-hour, 50-U/kg/hour heparin infusion, after which the APTT was allowed to return to baseline values spontaneously. In all 10 dogs, a thrombus was demonstrated only after cessation of the heparin infusion, and at a mean APTT ratio of 1.4 +/- 0.15 times baseline. These results suggest that, except with very early platelet injection, platelet accretion by thrombi is consistently inhibited by heparin at APTT ratios greater than 2.5. Platelet accretion by venous thrombi occurs within narrow limits of heparin effect as reflected by the APTT.
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PMID:Indium-111-labeled platelets: effects of heparin on uptake by venous thrombi and relationship to the activated partial thromboplastin time. 709 73

Heparin of five commercially available brands was used to study the disappearance of heparin anticoagulant activity in normal humans. The drug was administered intravenously by bolus injection and by continuous infusion. Heparin anticoagulant activity was determined by two assays: a diluted activated partial thromboplastin time (APTT) and an assay based on inactivation of bovine factor Xa, using a clotting system. After a bolus injection, the data fitted neither single exponential nor zero-order clearance. In semilogarithmic plots, heparin anticoagulant activity disappeared according to a slightly convex curve almost always preceded by a rapid initial loss of heparin anticoagulant activity. This disappearance profile was observed with all heparin regardless of the brand or assay system. Heparin anticoagulant activity estimated by the APTT disappeared faster than heparin anticoagulant activity estimated by the anti-Xa activity in the first phase. As expected, higher anticoagulant levels with the anti-Xa assay than with the APTT were also found on continuous infusion in normals as well as in patients treated for deep vein thrombosis or pulmonary embolism. The experimental data suggested a model based on the combination of a saturable and a linear clearance mechanism. These experimental data provide reliable guidelines for adjustment of the dose of heparin in single patients.
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PMID:Kinetics of intravenously administered heparin in normal humans. 713 19


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